不同方法制备GDC纳米粉体及其作为SOFC单电池阻挡层的应用研究

GDC Nano-powders Prepared via Different Methods and Their Application as Interlayer for Single Cell of SOFC

分别以尿素和NH4HCO3为沉淀剂通过沉淀法制备纳米GDC(10 mol%Gd2O3掺杂CeO2)粉体,研究对比两种GDC粉体的形貌及其烧结体的烧结性能和电性能。实验结果表明:以NH4HCO3为沉淀剂制备的粉体呈纳米球形,有利于致密烧结(1380℃烧结可达96%相对密度),适合作为制备SOFC(固体氧化物燃料电池)单电池(NiO+YSZ||YSZ||GDC||LSCF)阻挡层的流延原料。在700℃,以3%H2O+H2为燃料,空气为氧化气体,测得单电池的功率密度为0.66 W/cm2。而以尿素为沉淀剂制备的GDC粉体尺寸较大、产率低且呈类棒状,不利于密堆积,与YSZ的球形形貌迥异导致层与层的结合不紧密,采用同种方法制备及同种条件下测试,其功率密度仅为0.42 W/cm2。

GDC （10mol％Gd2O3 doped CeO2） nano-powder was prepared using urea and NH4HCO3 as precipitants via the method of precipitation.The nanopowder prepared using NH4HCO3 as precipitator had spherical morphology.It could effectively promote sintering densification （the theoretical density sintered at 1380 ℃ could reach 96％） and was appropriate to be used as the material for tape casting the （NiO＋YSZ‖YSZ‖GDC‖LSCF） interlayer for single cell of SOFC.The sintering performance and electrical properties of the two kinds of GDC nano-powders were studied.The maximum power density of the single cell was 0.66 W/cm2 when 3％H2O＋H2 was used as the fuel and the air as the oxidizing gas at 700 ℃.The GDC nanopowder prepared using urea as the precipitator,large in particle size and low in productivity,had rodlike structure.The morphology,utterly different from the spherical of the YSZ and unfavorable for densely packing,could result in a loose bond between two layers.So the maximum power density of the single cell prepared and tested in the same way was only 0.42 W/cm2.